Demco Brake Actuator - DM8759933

Applies your drum brakes on your hard-working trailer. Made in the USA with a corrosion-resistant, self-lubricating lining, so rest assured it'll last for a long time. Weld it, paint it, attach your own coupler, and get back to work!

Features:

• Hydraulic actuator activates trailer's brakes when tow vehicle slows or stops - no brake controller needed
• Manual reverse lockout lets you reverse without actuating your trailer's brakes
  • Rotate tab on actuator to left before backing up to activate lockout
• Adjustable channel has 3 different mounting positions for coupler (sold separately)
  • Channel-down design allows for greater drop
  • Compatible with a lunette ring, clevis, or ball coupler
• Composite master cylinder is durable and efficient
  • Glass-reinforced nylon construction resists rust and corrosion
  • Large reservoir provides increased capacity for brake fluid
  • Automotive-style diaphragm cap creates completely enclosed system to help prevent contamination of fluid
• Bearing-like lining inside the actuator eliminates the need for grease or lubricants
• Breakaway included
• Heavy-duty steel construction
• Primed finish lets you give it a custom paint job
• Weld-on installation
• Made in the USA

Specs:

• Application: trailers with hydraulic drum brakes
  • Designed to fit 3" wide trailer tongue
• Gross towing weight: 8,000 lbs
• Maximum tongue weight: 800 lbs
• Channel width: approximately 3"
• Channel height: 8"
• Model number: DA91
• 1-Year warranty

Tech Tip: If don't already have brakes that are free-backing, you'll need to get some. Otherwise, your brakes will keep locking up on you when you're backing up. And trust us on this one - upgrading now will be a lot less work than upgrading your wiring harness and a compatible actuator with an electric lockout.

Back Up Without Locking Up Your Brakes - Manual Reverse Lockout

If dont have either a 5-pole flat connector or your brakes that arent free-backing, youll need some other way to prevent your brakes from locking up on you when youre in reverse. With a manual reverse lockout, this actuator lets you do just that.

To use it, just rotate the tab on the side of the actuator to the left. Itll prevent the actuator from telescoping. When youre done backing up, youll want to make a good habit out of always remembering to restore the tab to its original position before towing normally.

Adjustable Channel Design

The adjustable channel on this trailer brake actuator allows for ultimate versatility. Mount almost any type of coupler (sold separately) - from a standard ball coupler to a lunette ring or clevis attachment - to fit your specific application. In addition, the 3 mounting positions on the channel let you adjust the height of the coupler. Just place the coupler so that it matches the height of the ball mount or other hitch attachment on your tow vehicle and you will be able to tow your trailer levelly.

This actuator is great for tall trailers. This is because the adjustable channel is positioned so that the mounted coupler can sit below the actuator tube, allowing for a greater drop than with a standard center-mounted channel. As a result, you can line up your tall trailer with your tow vehicle's hitch for a level setup.

Hard Plastic Lining for a Trailer that Sees Hard Labor

Acetal copolymer is a super-durable plastic, and you'll probably never break it. With a self-lubricating surface that's extremely resilient, smooth, and wears well over time, it's perfectly suited for this actuators inner member to help it glide as it telescopes. In fact, this same material is often used to make plain bearings and even has some automotive applications, making it perfectly suited for a life of hard labor, whether you're on the farm or from one jobsite to the next.

How Does a Surge Brake Actuator Work?

When you're towing, the momentum of your rig pushes and pulls on your hitch ball as you slow to a stop. And with a surge brake actuator, that momentum uses the coupling point to push back on the inner portion of your surge brake actuator, which then compresses the master cylinder inside. As it contracts, it pressurizes your hydraulic brake lines, and ultimately engages your trailer brakes. When you start moving again, your tow vehicle pulls that inner portion back out, allowing the trailers wheels to start rolling again.

8759933 Demco DA91 Hydraulic Trailer Brake Actuator for Drum Brakes - Channel Down - 8,000 lbs